Acute and chronic pain management has been a concern for as long as medicine has been practiced. Several methods of inducing analgesia and anesthesia have been developed. For example, the use of chemical substances is perhaps the most common approach to pain relief which requires suitable substances that are effective, safe to humans, and do not cause complications or abnormal reactions. Despite the great advances that have been made in the field of anesthesiology, and in the field of pain relief in general, there are still some drawbacks to chemical-based approaches. For instance, the anesthetics generally available today must be administered in carefully graduated doses to assure the patient's wellbeing, require extended periods of fasting prior to treatment, and are often accompanied by undesirable after effects such as nausea.
One alternative approach that is commonly used for providing pain relief is ablation in which nerves and/or soft tissue is removed and/or destroyed. Two approaches to removing tissue via ablation are through cold or hot ablation procedures and techniques. Various categories of ablation include but are not limited to electrical, radiation, light, radiofrequency, ultrasound, cryotherapy, thermal, microwave and hydromechanical. One form of hot ablation is radiofrequency ablation. During radiofrequency (RF) ablation, current passing through tissue from the active electrode leads to ion agitation, which is converted by means of friction into heat. The process of cellular heating includes almost immediate and irreparable cellular damage, which leads to coagulation necrosis. Because ion agitation, and thus tissue heating, is greatest in areas of highest current density (e.g., closest to the active electrode tip), necrosis is limited to a relatively small volume of tissue surrounding the RF electrode.
A form of cold ablation is cryoablation. During cryoablation, tissue is frozen or rapid freeze/thaw cycles are inflicted upon the tissue. There are many advantages to using cryoablation instead of radiofrequency ablation. For example, cryoablation is safer especially near critical vasculature and there is less risk of post-procedure neuritis or neuromas following neuroablation for the treatment of pain. Cryoablation allows treatment mapping pre and post procedure where areas of tissue can be mapped by limited, reversible and/or freezing. Cryoablation can be monitored and visualized on ultrasonography, CT and MRI. Moreover, because nerve cooling is anesthetic, cryoablation is a less painful procedure than thermal ablation techniques.
Other ways of removing soft tissue and nerves utilize cutting instruments like a scalpel or cutting blade. However, when dealing with soft tissue and nerve areas particularly in a delicate area, such as for example, the spinal column, cutting, retraction and removal of tissue can be complicated particularly when multiple entries are required to repair the surgical site. There is often unwanted collateral damage to soft tissue and nerve areas. For example, hypertrophic ligamentum flavum is a prevalent soft tissue disorder that causes pain in patients and is associated with spinal stenosis. This disorder is often treated by decompression of the spine, which often times requires multiple entries into the spine to remove and cut the surrounding tissue. This is not only painful to the patient, but also can lead to complications and prolong the surgical and recovery times.
Accordingly, there is a need for devices and methods that provide efficient removal of nerve and/or soft tissue while reducing or limiting unwanted damage to tissue surrounding the surgical site. There is also a need for devices and methods that allow capture, cutting and removal of soft tissue and nerve areas at or near a surgical site.